The present invention relates to spray guns and more particularly to hand held sprayers adapted for spraying texturizing material onto surfaces such as ceilings, walls, floors, etc.
State of the art spray texturizing systems typically employ a hand held gun which utilizes a carrier fluid such as air from a pressurized source to entrain a synthetic material such as drywall texturing mud or ceiling material. The systems include a housing in the form of a pistol grip at the rearward portion and a material dispersing bowl at the forward end terminating in a nozzle. An air delivery tube slidably mounted in the housing delivers a high velocity air stream to the nozzle via an air duct in the handle. A conventional compressor supplies the air to the handle air duct via a flexible line. The material dispensing bowl is in the form of an elbow with the nozzle positioned at the forward end, an opening opposite the forward end for receiving the air delivery tube and a right angle extension through which the texturizing material is pumped (or flows by gravity) from a reservoir.
The state of the art texturizing spray guns have several shortcomings. First, the flexible line or conduit extending from the pump to the spray gun, when full of the material to be sprayed, is heavy. The weight of the filled line from floor level to the hand gun level is burdensome and particularly so when surfaces to be coated are above the operator""s head are to be coated. A gravity feed system, where the reservoir of texturizing material is carried by the gun, like the line fed system, presents a tiring load on a operator""s arm and hand holding the gun. In addition the gravity feed systems are not conducive for overhead spraying.
Second, the ninety degree (90xc2x0) angle between the material extension and the air flow path seems to impede the smooth flow of material through the nozzle.
There is a need for a hand held spray gun adapted to apply texturizing and other coating material which overcomes the above shortcomings.
A spray gun adapted for applying texturized coatings, in accordance with the present invention, includes a housing having an upper portion terminating at its forward end in a mounting block with a longitudinal bore extending therethrough. The lower portion of the housing forms a pistol grip with a carrier fluid (e.g., air) passageway therein extending from an inlet port at the lower end to the longitudinal bore. A carrier fluid delivery tube is positioned within the housing""s longitudinal bore with the distal end of the tube extending beyond the mounting block and terminating in a discharge orifice. The proximal end of the delivery tube is in fluid communication with the carrier fluid passageway.
A coating material/carrier fluid interface member is rotatably mounted on the mounting block and comprises a central section with an axial bore aligned with the longitudinal bore and surrounding the distal end of the deliver tube with the outlet orifice disposed adjacent the forward end of the interface member.
The interface member further includes a material inlet nipple extending outwardly from the central section along an axis which intersects the axis of the longitudinal bore. The inlet nipple defines a material inlet chamber which is in fluid communication with an aspiration chamber within the central section of the interface member. Preferably the material inlet chamber intersects the longitudinal bore at an acute angle to enhance the flow of coating material into the air stream exiting the delivery tube outlet orifice. A nozzle is secured to the forward end of the interface member to provide a desired output spray pattern of the coating material/carrier fluid.
The interface member may be rotated relative to the housing to a desired position to accommodate a material feed line extending downwardly from the gun or a line extending upwardly from the gun and supported, for example, by the operator""s shoulder and back. As an optional feature a swivel joint coupling may be used to connect the air line to the housing inlet port so that the air line as well as the coating material feed line can be positioned over the operator""s shoulder.